Population Concern
a U.K. based organization working in partnership with local organisations in less developed countries to provide information, education and services relating to sexual and reproductive health.

Population Connection, formerly ZPG, U.S. -
an established organization, originally dedicated to Zero Population Growth, now has a rewritten mission statement which supports sustained population growth and deliberately ignores 70% of U.S. population growth - mass immigration. (Although they do have excellent educational materials).

Population Council, U.S.,
is a nonprofit research organization seeking to improve well being and
reproductive health, and to help achieve a sustainable balance between people and resources. Includes references, links, and search engine.

Population Environment Balance, U.S.,
works to educate and impress upon the American public and policymakers the adverse effects of population growth on the environment.

The Population Reference Bureau , U.S.,
is a nonprofit, nonadvocacy, educational organization. It was founded in 1929 and is America's oldest population organization. They provide
PopNet,
a comprehensive source for global population information. Unfortunately, recently they have strayed from providing factual population information and now focus their magazine on Politically Correct social issues.

USAID Population, Health and Nutrition (PHN), U.S. -
programs focus on family planning, child survival, prevention of HIV/AIDS and
other sexually transmitted infections, maternal health and nutrition, and health
system reforms.